Tobacco use in childhood associated with lower cognitive function, reduced brain structure

Initiating tobacco use during childhood was associated with inferior cognitive function and reduced brain structure, researchers reported in JAMA Network Open.

Hongying Daisy Dai, PhD, associate dean of research at the University of Nebraska Medical Center, and colleagues aimed to assess the association between early-age initiation of tobacco use and cognitive performance measured by the NIH’s Toolbox Cognitive Battery, as well as examine whether initiation is associated with differences in brain morphometry.

Dai and colleagues conducted an observational cohort study that examined longitudinal associations of the initiation of tobacco use with neurocognition using multivariate linear mixed models.

A total of 11,729 children aged 9 to 10 years from 21 American sites were enrolled from October 2016 through October 2018. A total of 10,081 children were assessed at the 2-year follow-up from August 2018 to January 2021.

Among the 11,729 children assessed at wave 1 (mean age, 9.9 years; 52.1% male; 52.1% white), 116 children reported ever using tobacco. After controlling for confounders, tobacco ever users compared with nonusers exhibited lower scores on the Picture Vocabulary Test at wave 1 (–2.9) and at the 2-year follow up (–3). Cognition composite scores were also lower among tobacco ever users compared with nonusers at wave 1 (–2.4) and at the 2-year follow up (–2.7).

When the authors assessed structural MRI, the whole brain measures in cortical area and volume were significantly lower among tobacco users than nonusers including cortical area at wave 1 (–5,014.8 mm² ), and cortical volume at wave 1 (–174,621 mm³) and after the 2-year follow-up (–21,790.8 mm³).

“Our results showed that tobacco ever users continued to have significantly lower scores in higher-order cognitive functions, particularly in oral reading recognition, auditory comprehension and crystallized intelligence, compared with nonusers,” the authors wrote. “These cognitive functions relate to verbal and reading capacity and are more dependent on past learning experiences.”

In a related editorial, Steven R. Laviolette, PhD, a professor in the department of anatomy and cell biology at the Schulich School of Medicine & Dentistry at the University of Western Ontario in Canada, said Dai and colleagues presented “compelling and novel” data that demonstrate “significant and deleterious associations” of childhood smoking and nicotine exposures with neurodevelopmental and cognitive measures.

“The findings reported by Dai and colleagues raise many important questions for future clinical and preclinical investigations,” Laviolette wrote. “Notably, it will be important to determine how persistent these pathophysiological outcomes remain beyond the windows of prepubertal and adolescent brain maturation. In addition, it will be critical to identify the specific molecular mechanisms and biomarkers underlying these enduring, tobacco-induced pathophysiological outcomes.”

Reference:

Laviolette SR, et al. JAMA Netw Open. 2022;doi:10.1001/jamanetworkopen.2022.26001.